Ultimate Lateral Shear Capacity of Steel Frames With Inverted v Braces

Numerical simulation of the cyclic‐loading behavior of steel chevron‐braced moment‐resisting frames

“…Furthermore, $$$ \kappa $$$, $$$ 1.0\le \kappa \le 2.0 $$$, is the assumed limit for the maximum possible unbalanced vertical force over the plastic resistance of the beam, $$$ {V}_{b0}=4{M}_p/l $$$, when subject to reverse end moments $$$ {M}_p $$$. The factor $$$ \kappa $$$ addresses the beam end moments that act in combination with the unbalanced vertical force 3,4,15 . The maximum value$$$ \kappa =2.0 $$$ corresponds to the case when both end moments $$$ {M}_p $$$ act in the direction to oppose the unbalanced vertical force.…”

“…The maximum value$$$ \kappa =2.0 $$$ corresponds to the case when both end moments $$$ {M}_p $$$ act in the direction to oppose the unbalanced vertical force. Fukuta et al 3 . recommended $$$ \kappa =1.0 $$$ to avoid yielding the beam intersected by braces.…”

“…A key focus of the project was the beams intersected by braces. Unlike the beams in chevron CBFs that are simply supported at the ends, the beams in chevron‐braced MRFs cannot be evaluated straightforwardly 3,4,15 . Their resistance against unbalanced vertical forces depends on the bending moments developed at the beam ends, which in turn is a function of the cyclic loading history experienced by the structural system.…”

“…Experiments by Shibata and Wakabayashi 1 and Yamanouchi et al 2 demonstrated that, if the beam is not provided with sufficient strength to sustain the unbalanced vertical force, then beam yielding may dictate the seismic performance of the chevron-braced MRF. Fukuta and Yamanouchi 3 and Inoue and Shimizu 4 proposed a design rule to proportion such beams intersected by braces which will be discussed in the next section.…”

“…Unlike the beams in chevron CBFs that are simply supported at the ends, the beams in chevron-braced MRFs cannot be evaluated straightforwardly. 3,4,15 Their resistance against unbalanced vertical forces depends on the bending moments developed at the beam ends, which in turn is a function of the cyclic loading history experienced by the structural system. The experimental component of the project is reported by Seki et al 15 This paper summarizes the computational component of the project whose objective was to further the understanding obtained from the experimental observations.…”